1. Field of the Invention
This invention relates to an anti-theft security system for computers using a universal serial bus port. In particular, the invention relates to a sensor integrated with a universal serial bus connector that connects the computer or peripheral with a central alarm system, so that if the connecting cable is cut or damaged, or the connector is disconnected, an alarm is triggered at the central alarm system.
2. The Prior Art
Computers in large business establishments, and especially those on display in electronics stores, are highly prone to theft. Therefore, many computers are manually locked to the workstations or display shelves with a bicycle-type lock to prevent theft. These locks, however strong, can often be broken and the computer then stolen, with no detection. Large work spaces or retail computer stores can have large numbers of computers in one small area, and would thus be at a great loss if the computers were stolen.
It is therefore an object of the invention to provide an anti-theft security system for computers that immediately alerts the owner if theft or tampering occurs.
It is another object of the invention to provide an anti-theft security system for computers that also prevents theft of peripherals such as scanners, printers and other machines.
It is yet another object of the invention to provide an anti-theft security system that can protect large numbers of computers and peripherals with a single central alarm unit.
It is a further object of the invention to provide an anti-theft security system that can be used on any brand of computer or peripheral having a universal serial bus port.
These and other objects of the invention are accomplished by a computer anti-theft security system comprising a USB connector having a housing section and a connector connected to the housing section. A cable is connected to the connector and extends through the housing section. The connector inserts into a USB port of a computer or peripheral and the cable is then connected to a central alarm monitoring unit. A sensor is disposed within the housing and connected to the cable as well. If the USB connector is disconnected from the computer or peripheral, or if the cable is cut, an alarm sounds from the central alarm monitoring unit. The USB connector is built like a standard USB connector, such as disclosed in U.S. Pat. No. 5,725,395 to Lee or U.S. Pat. No. 5,725,386 to Davis et al, both of which are herein incorporated by reference.
The central alarm monitoring unit is preferably that disclosed in U.S. Pat. No. 5,821,857 to Rand, the disclosure of which is herein incorporated by reference. Many USB connectors with sensors can be connected to a single central alarm monitoring unit, so that an entire store or office full of computers and peripherals can be protected with a single alarm unit.
USB connectors are divided into two types: Type xe2x80x9cAxe2x80x9d and type xe2x80x9cBxe2x80x9d. Type A connectors are oriented upstream toward the host system, i.e., connected to the computer. Type xe2x80x9cBxe2x80x9d connectors are oriented downstream of the host system, i.e., connected to the peripheral. The system according to the invention can use either type A or type B connectors, or both.
The USB connector is dimensioned and configured to fit commercially available computers and peripherals. The connector portion has a data+ and a dataxe2x88x92 terminal, which are connected to ground through a 15 kxcexa9 resistor within the computer or peripheral. The general specifications for the connector portion and the dimensions of the USB connector according to the invention are well known in the art and are also disclosed in Universal Serial Bus Specification Revision 1.1, Chapter 6, pages 73-105, Sep. 23, 1998, available at www.usb.org/developers/data the disclosure of which is herein incorporated by reference.
The cable is preferably a four conductor cable. The sensor within the USB connector according to the invention includes a light emitting diode (LED) connected to two wires in the cable. The LED is preferably bicolor and glows one color, i.e., green, when the connector is connected to a computer or peripheral and to the central alarm unit. The LED glows red when the connector is disconnected in any way, indicating an alarm status. There is an electro-mechanical switch (EMS) that is activated to control the LED.
The sensor also includes a diode connected to the other two wires within the cable and to the computer or peripheral through the connector. The diode serves to indicate the presence of the sensor to the central alarm monitoring unit when the switch is open. The sensor works as follows: When the USB sensor is initially connected to the central alarm monitoring unit, the LED glows red, since the central alarm monitoring unit detects the presence of the sensor. Upon plugging the connector into the computer or peripheral, the electro-mechanical switch (EMS) is activated. The EMS sends a signal to illuminate the LED green, and alert the central alarm monitoring unit of a sensor condition. If the EMS is not activated, the circuit sends a signal to illuminate the LED red. Therefore, if the central alarm monitoring unit does not detect the return signal, either the connector is dislodged or the cable is broken. In either case, the central alarm monitoring unit will register an alarm and the LED on the sensor will switch from green to red.
The system according to the invention can be manufactured to be xe2x80x9csupervisedxe2x80x9d or xe2x80x9cnon-supervisedxe2x80x9d. In the supervised configuration, the system is constantly monitoring the sensor. If someone attempts to bypass, short, sever or tamper with the EMS or cabling, this will interrupt the current running through the system and thus tamper with the system, the sensor will detect this interference through registering a change in the voltage, and sound the alarm. In the non-supervised configuration, the alarm will sound only if the connection to the control unit is severed or if the EMS is deactivated.